Research And Implementation Of Programmable Digital Power System

As a common electronic instrument,the essence of power supply is the energy conversion device that provides power to electronic equipment.With the increase of electrification of human society,the demand for power supply is becoming higher and higher.The conversion efficiency,output ripple noise,volume and weight of power supply have become an important research direction to improve the performance of power supply.However,the improvement of power output quality is often at the cost of increasing the loss and volume of the system.This topic adopts the composite structure of switching voltage stabilized power supply and linear voltage stabilized power supply,which effectively solves the contradiction between power output performance and efficiency.It has strong engineering application value and certain academic research significance.The main research contents and results of this paper are as follows:Firstly,the switching voltage stabilizer and the principle of linear regulated power supply and architecture are studied,this paper analyzes the strengths and weaknesses of the switch power supply and linear power supply,this paper proposes a STM32F746 as control core,at the same time,both the advantages of switching power supply and linear regulated power supply hardware design scheme of the switch power supply adjustment after add linear voltage adjustment scheme,Ensure that the output voltage ripple is small,high efficiency,light weight and other characteristics.And through the design of the tracking circuit,the tracking of the front switch output to the rear linear voltage regulator output is realized,the constant pressure difference control of the linear voltage regulator part is completed,and the loss of the linear voltage regulator due to the increase of the input and output pressure difference is reduced when the output voltage changes.Through simulation analysis,the feasibility of switch plus linear two-stage linkage scheme is verified.And on the basis of the adjustable main circuit design scheme,the design and simulation verification of the peripheral circuit based on the monitoring chip AD7292 are improved,such as amplifier circuit,sampling circuit,adder circuit and so on.Adder circuit is innovatively adopted to combine two 10-bit Digital to Analog Converter(DAC)of AD7292 into 15-bit DAC,which makes the power supply system reach 1MV programmable precision.Secondly,in order to solve the problem of poor real-time performance of traditional power supply,a software scheme based on Free RTOS real-time operating system is proposed,which can flexibly allocate system resources and manage tasks by using the real-time operating system.At the same time,aiming at the deficiency of traditional DC regulated power supply in man-machine interaction design,a Synchronous Dynamic Random Access Memory(Synchronous Dynamic Random Access Memory)is designed by STM32F7 processor,LCD touch screen,SDRAM chip and power supply module are composed of programmable digital power LCD touch display system.The LCD screen is directly driven by STM32F7,and the external SDRAM is extended as video Memory through the Flexible Memory Controller(FMC).The power module provides the backlight voltage power supply for the display screen,and the graphical interface is designed by using Emwin.The experimental results show that: The display effect of the system is clear,and it can control and monitor the power system in real time,which provides a reference for the application of the touch screen in the power field.Finally,the physical debugging of each module and the production of power prototype are completed,and the performance of the prototype is tested and analyzed in detail.The experimental results show that the power supply can be adjusted in the range of0-32 V and 0-3A,the load adjustment rate is less than 0.5%,ripple noise is less than1 MVRMS,the voltage accuracy is 0.03% ±8m V,the maximum efficiency of single channel can reach 80%,the weight of the whole machine is 2.4kg.A programmable digital power supply with high efficiency,high precision,real-time monitoring,low ripple and light weight is realized,which provides a new power supply design scheme for the power supply field.